Diffusion in ', at between 1298 and 1573K, was studied by using the diffusion couple: Ni-24.2Al/Ni-20.9Al-3.17at%Ti. The diffusion profiles were measured by using an electron probe micro-analyzer, and the diffusion coefficients of Ti in ' which contained 24.2at%Al, were deduced from those diffusion profiles by using the Hall method. The temperature dependence of the diffusion coefficients was given by:

D(m2/s) = 56 exp[-468(kJ/mol)/RT]

Tthe Ti atoms, which occupied cubic corner sites, diffused according to a larger activation energy that included the energy which was due to local disordering caused by atomic jumps.

Y.Minamino, S.B.Jung, T.Yamane, K.Hirao.: Metallurgical Transactions, 1992, 23A[10], 2783-90